Apparatus for controlling buckle in heated steel billets



June 15, 1 965 3,189,338

APPARATUS FOR CONTROLLING BUCKLE IN HEATED STEEL BILLETS P. E. SMITH 2Sheets-Sheet 1 Filed Jan. 26, 1962 H o'rneys June 15, 1965 P. E. SMITHAPPARATUS FOR CONTROLLING BUCKLE IN HEATED STEEL BILLETS Filed Jan. 26,1962 2 Sheets-Sheet 2 INVENTOR. Paul E; Smith United States Patent3,189,338 APPARATUS FOR CONTROLLDJG BUCKLE IN HEATED STEEL BELLETS PaulE. Smith, Worcester, Mass, assignor to Morgan Construction Company,Worcester, Mass., a corporation of Massachusetts Filed Jan. 26, 1962,Ser. No. 168,970 6 tCiaims. ((21. 266-) This invention relates generallyto an apparatus and method for traversing a steel billet across aholding furnace hearth and more particularly to a method and apparatusfor preventing buckling of a heated billet during the push-outoperation.

One of the methods now in use in the steel industry to convey aplurality of individually charged billets across a furnace hearth is theuse of a broadwise actuated ram mechanism which will engage each of theindividual billet member as they are endwise inserted at one end of thefurnace. Repeated cycling of the ram mechanism forces the billetbroadside a distance sufficient to allow a second billet to be endwisecharged to take the place thereof. Repeated cycling of the ram mechanismforces the aligned billet members across the furnace hearth to theopposite end thereof where a push-out arm acts on the end of the billetto eject the heated billet from thefurnace. This method has provenentirely satisfactory as long as billet lengths are kept under 35 footlengths. However, recent innovations in the manufacture of steel and itssubsequent processing has resulted in a demand for longer billet lengthsup to the magnitude of 90 feet. By providing billet lengths which are inexcess of 35 feet, larger coils may be produced during the subsequentrolling operation. The increase in coil size from the average of 800lbs., now produced by conventional methods, to coils weighing 2000 lbs.ultimately saves handling of coils, results in bigger bundles andincreases the efiiciency and economy of the metal rolling operation. Theconventional method of handling billet lengths of this size or anythinggreater than 35 feet has resulted in buckling of the billet within thefurnace due to the frictional resistance of hearth and the weight of thebillet, counteracting and resisting the forces exerted by the push-outarm on the end of the relatively flexible heated billet. Since thesebillets normally are dimensioned 2%" x 2% x 88 feet, they have a weightof approximately 2000 lbs., and any buckle which takes place within thefurnace area itself causes extreme difiiculty which may require theshut-down of the furnace until the cobble can be removed. As thesebillets are normally heated to approximately 2100 F. buckling may causea fusion of the cobbled member to other billets so that the entirefurnace load is rendered unfit for further processing and must bediscarded.

Therefore it is an object of this invention to provide an apparatus andmethod for traversing long billets across a furnace hearth and tominimize or eliminate the buckling during the push-out operation.

It is a further object of this invention to provide an apparatus andmethod for imparting an arcuate formation to normally straightdimensioned bars after they are positioned within the furnace and tomaintain them in this arcuate position as they traverse across thefurnace hearth to the push-out mechanism.

Patented June 15, 1965 Broadly stated in the attainment of the foregoingrelated advances, a holding furnace is provided having a plurality ofpusher bars extending through one end wall thereof and connected to acentral drive mechanism located externally of the furnace so that eachof the pusher arms extends inwardly at varying distances from the endwall of the furnace with the outermost ends extending inwardly a greaterdistance from the end wall than those toward the center line. In thismanner the free ends of the pusher bars present a curvilinear line whichtravels through a constant lateral path in response to the movement ofthe central drive mechanism.

To the accomplishment of the foregoing and related ends, the presentinvention then consists of the means hereinafter fully described, andparticularly pointed out in the claims, the annexed drawing and thefollowing description setting forth in detail certain means of carryingout the invention, which disclosed means illustrating, however, but oneof the various ways in which the principles of the invention may beemployed. The present invention is illustrated by way of example.

In the accompanying drawings in which:

FIG. 1 is a top plan view partly in section of the furnace embodyingfeatures of this invention;

FIG. 2 is a view in section taken on line 2--2 of FIG. 1; and

FIG. 3 is a view in section taken on line 33 of FIG. 1.

Reference is now to be had to the drawings where an illustratedembodiment of the holding furnace construction made in accordance withthe present invention and generally designated by the reference numeral10 is shown. The furnace construction 19 is of the conventional typehaving end walls 12 and 14 and side walls 16 and 18. The side wall 16has an aperture 20 formed therein adjacent the end wall 12 and adaptedto receive a billet 22 which is presented endwise by an arm 24 ofcharging mechanism 26. The charging mechanism 26 is of the reciprocatingtype and is adapted to linearly travel along rollers 28 which are drivenby a motor 30 through a suitable reduction gear 32 to aid in conveyingthe billet 22 to the interior of the furnace 10. On the same side wall16 of the holding furnace 10 and at a point adjacent the end wall 14 asimilar aperture 34 is formed adapted to receive a push-out arm 36 whichis actuated through a suitable reciprocating mechanisrn 38 and whichserves to eject the billet after it has travelled across the hearth 40of the holding furnace 10. On the opposing side wall 18 adjacent the endwall 14, and in alignment with the aperture 34 is another aperture 42which allows discharge of a billet fr'om the furnace where it ischannelled by guide means 44 to roll stand 46 which lies directly in thepath of further rod processing equipment (not shown).

Spaced from the end Wall 12, but parallel thereto, is a reciprocatingram mechanism 48 including a motor 5t) and a reduction gear 52 whichdrives a longitudinally extending shaft 54 coupled at the ends totransversely extending arms 56 and 58. The arms 56 and 58 are adaptedfor movement by means of gearing 59 which converts the rotary motion ofthe shaft 54 into linear motion along a plane normal to the end wall 12.As can be seen from referring to FIG. 1 the arms 56 and 58 are securedto a longitudinally extending bar member 60 which is adapted forcorresponding movement therewith. A plurality of pusher bars 62 whichmove in the same direction as the arm members 56 and 58 are connected atone end to the bar member 60 and adapted to ride on suitable bearings64. A plurality of corresponding apertures 66 are formed in the end wall12 in axial alignment with the pusher bars 62 to permit the entry of thepusher arms within the interior of the furnace 10. The pusher bars 62are of different lengths with the shorter bars situated substantially atthe center of the end wall 12 and the bars extending on either side ofthe center bar incrementally longer than the preceding bars so that theoutermost bars extend inwardly a greater distance from the interior edge67 of the end wall 12 than the centermost arms. In this manner aline'drawn connecting the free ends 68 of the pusher arms 62 will definean arcuate path.

Referring to FIG. 2 there is shown a cross sectional elevation of thefurnace illustrating the hearth 4t having a concave shape so that thecenter portion 7% curves downwardly from theportions 72 and 74 which areadjacent the side walls 16 and 18. The action of the charging arm 36 onthe end of the billet 22 to eject the billet from the furnace throughthe opening 44 so that it may ,be picked up by the guide 44 for deliveryto the roll stand 46 is thereby shown.

In FIG. 3 there is shown an enlarged view in section of the pusher bars62 extending through the end wall 12 before the pusher bars have beenactuated by the operating mechanism 48 and illustrate the billet 22 inposition to receive a broadside thrust from the pusher bars 62.

In the operation of this apparatus the billets 22 are charged into thefurnace by the charging arm 24 so as to lie at a position which isspaced from the end wall 12. The motor 50 operating through thereduction gear 52 rotates the shaft 54 to impart a transverse motion tothe arms 56 and 58 which in turn moves the pusher bars 62 by means ofthe longitudinally extending bar member 66 so that each of the barmembers 62 moves simultaneously with each other to impart a broadsidemotion to the billets 22. In this manner it will be seen that theoutermost pusher bars 62 make contact with the billet member first,forming the billet into an arcuate shape and at the same time pushing itaway from the end wall 12. As successive billets are presented by thecharging mechanism 26 they are similarly acted upon by the pusher bar 62and impart a thrust to previously charged billets which have alreadybeen transversely moved along the furnace hearth floor 40. The hearth 40having a concave configuration allows the billet 22 to curve downwardlyat the center portion so that the ends 76 and 78 are in a higher planethan the center portion. The broadwise force exerted on each newlypresented billet 22 by the pusher bars 62 is also imparted to thebillets already in the furnace until the furnace is fully charged. Thepush-out arm 36 is synchronously timed with the charging mechanism 26 toeject the billet after it has passed across the hearth. The billet 22after passing across the furnace hearth has been raised to a temperaturein the range of 2100 and as the push-out arm 36 acts on the end of thebillet to eject it from the furnace the billet has a pre-disposition tobuckle in the direction of the concave surfaces. The billet, however, isprevented from buckling by the weight of the successively horizontalstacked billets which extend in the direction of the concavity and alsoby the force exerted on them by the pusher bars 62. Furthermore, to aidin keeping the billets with their lateral surface in abuttingrelationship, the hearth 40 may be inclined upwardly from the'rear Wall12 toward the front wall 14, as shown in FIG. 3 in broken lines. In thismanner the gravitational effect on the billets will maintain an opposingforce relative to the action of the pusher bars 62. The billet 22 alsohas a tendency to buckle downwardly due to the arcuate formationpresented to it by the formation of the concave hearth but is resistedfrom doing so by the 'hearth itself. Consequently, any tendency of thebillet to buckle in the direction of either of its arcuate formations isprevented, and since the billet would have to overcome the deformationof the center position and go beyond a straight linear dimension beforeit could buckle either upwardly or in a direction opposite to itshorizontal deformation, buckling of the billet during the ejection stageis circumvented.

Therefore, a ram mechanism utilizing pusher bars having varying lengthsto impart an arcuate formation to the billet length and having a hearthwhich also allows a downward arcuate formation to the bar member permitsthe use of billets which are in excess of 35 feet without the danger ofbuckling during the push-out operation.

Since certain obvious modifications may be made in this apparatuswithout departing from the scope thereof, it is intended that all mattercontained herein be interpreted in an illustrative and not in a limitingsense.

I claim:

ll. Apparatus for conveying a plurality of billets through a furnacehaving side and end walls, said apparatus including means forsuccessively charging one end of the furnace with billets, areciprocating ram mechanism having a plurality of laterally spacedpusher bars of varying lengths extending into said furnace through oneend wall thereof with the outermost pusher bars extending inwardly agreater distance from said end wall than the innermost pusher bars,means for imparting motion to said ram mechanism so that said pusherbars exert a force on each billet normal to its greater dimension, andpush-out means acting on one end of the billet and disposed adjacent theopposite end wall of said furnace to remove individual billets from thefurnace.

2. Apparatus as set forth in claim 1 where the furnace hearth slopesupwardly from the end wall containing the pusher bars to the oppositeend wall.

3. Apparatus for traversing billets across a furnace hearth having sideand end walls, said apparatus including means for successively chargingone end of said furnace with individual billets presented endwisethrough a side wall of the furnace, a reciprocating ram mechanismadjacent one end wall of the furnace having a plurality of laterallyspaced pusher bars with end portions extending within said furnace, saidpusher bars being of varying lengths so that the end portions define anarcuate line relative to the end wall, means for imparting motion tosaid ram mechanism so that said pusher bars exert a force on each billetnormal to its greater dimension and push-out means extending throughsaid side wall adjacent the opposite end wall to eject the billets fromsaid furnace.

4. An apparatus as defined further in claim 3 where said furnace hearthhas a concave configuration with the area adjacent the side walls havinga higher elevation than the center section.

5. Apparatus for conveying a plurality of billets through a furnacehaving side and end walls, said apparatus including means forsuccessively charging endwise presented billets into one end of thefurnace, a plurality of laterally spaced pusher bars of varying lengthsextending through one end wall of said furnace with the outermost pusherbars extending inwardly a greater distance from said end wall than theinnermost pusher bars, means acting on said pusher bars to direct themnormal to the greater dimension of said billets, the hearth surface ofsaid furnace having a concave configuration with the area adjacent tothe side walls at a higher elevation than the center section, saidfurnace hearth sloping upwardly from said one end wall of the furnace tothe other end wall and pusher means adjacent said other end wall adaptedto eject said billets from the furnace.

6. A heating furnace for metal billets comprising side walls, front andrear walls, and a hearth sloping upwardly from the rear wall to thefront wall, said hearth having a concave surface with the area adjacentthe side walls having a higher elevation than the center section, meansfor successively charging endwise presented billets through oneapertured side wall adjacent the rear wall, a plurality of laterallyspaced pusher bars extending through the rear wall into said furnace,means for imparting a motion to said pusher bars normal to the greaterdimension of said billets, the end portions of each of said pusher barsdisposed Within said furnace and spaced from the rear Wall at varyingdistances so that the centermost end portion is closest to the rear walland the pusher bar end portions on either side thereof are spacedincrementally a greater distance from said rear Wall, and push-out meansextending through said one side Wall adjacent the front end Wall adaptedto eject said billets from the furnace.

References Cited by the Examiner UNITED STATES PATENTS 2,616,679 11/52Morgan 2636 X 3,055,650 9/62 Morgan 263-6 MORRIS O. WGLK, PrimaryExaminer.

DAVID L. RECK, Examiner.

1. APPARATUS FOR CONVEYING A PLURALITY OF BILLETS THROUGH A FURNACEHAVING SIDE AND END WALLS, SAID APPARATUS INCLUDING MEANS FORSUCCESSIVELY CHARGING ONE END OF THE FURNACE WITH BILLETS ARECIPROCATING RAM MECHANISM HAVING A PLURALITY OF LATERALLY SPACEDPUSHER BARS OF VARYING LENGTHS EXTENDING INTO SAID FURNACE THROUGH ONEEND WALL THEREOF WITH THE OUTERMOST PUSHER BARS EXTENDING INWARDLY AGREATER DISTANCE FROM SAID END WASLL THAN THE INNERMOST PUSHER BARS,MEANS FOR IMPARTING MOTION TO SAID RAM MECHANISM SO THAT SAID PUSHERBARS EXERT A FORCE ON EACH BILLET NORMAL TO ITS GREATER DIMENSION, ANDPUSH-OUT MEANS ACTING ON END OF THE BILLET AND DISPOSED ADJACENT THEOPPOSITE END WALL OF SAID FURNACE TO REMOVE INDIVIDUAL BILLETS FROM THEFURNACE.